I'm a new comer to 2 channel stereo. I have recently purchased ARC VT-130 power amp and Wadia 830 CDP which I'm currently feeding straight into the amp using PS Audio Statement XLR

Music however sounds a bit straight forward, lacking a bit the tube warmth. So I'm considering adding a matching tube preamplifier and I am currently looking for used one. Your suggestions are most welcome

I'm also looking to buy a pair of floorstanding speakers to be driven by my VT130 (for the moment I use my old Infinity speakers which were dedicated to my HT system...). Again greatly appreciate your suggestions

Finally do you have a recommendation for upgrading the interconnect (I was told MIT 330/350 or Cardas Golden Ref)?

I listen mostly to classical, opera, instrumental jazz and female vocals. My system is in my living room which is 25.5x19 feet

I owned the VT130 for a few years and very much enjoyed the musicality of this amp....especially with KT88 tubes which brought on a greater warmth and bloom than 6550 tubes. But the KT88's were a bit unreliable causing resistors in the amp to be destroyed. So if you are handy with a soldering iron and replacing components on the board, then this would only be a nuisance if it happened. This happened with JJ Tesla KT88 tubes so others may be fine.

As for a matching preamp, I assume you mean line stage only here. The ARC LS5 was an outstanding synergy here. This is often on the used market for $1800-2000 for the MK II, and $2300 or so for the MK III which I would suggest as it is a little more tonally coherent; the MK II for me at least had a rising top end. I owned the LS5 II for 7 years and the MK III for 1 year before upgrading to the BAT 31SE. Another consideration in the LS5 price range is the BAT 5i which also is a true balanced product. The BAT will trade off some top end extension but will bring on a more authoritative bass and even more of a warm presentation.

As far as speakers, products like B&W, Vandersteen work well here with a more mellow presentation vs. something more forward like Proac and Thiel. You really need to find that line stage first as this will set the stage for one heck of a musical system.

I found that Cardas Golden Cross was a super match as an IC between the LS5 and VT130 but using any more of this cable brings on too much of a good thing (warmth) and trades off resolution and clarity. I now use MIT 350 EVO and this is far far more neutral and resolving than the CGC but the Cardas Golden Ref might work very well here. NBS Signature is really the great cable for the value if you can live with 1-2m lenghts. I see these sell for the same as the CGC on the used market and the NBS is far far the more refined product.